Wattanachai, P., B. Buasathain, C. Antonio, dan S. Roces. Open Loop Recycling of Recycled Polypropylene for Motorcycle Saddle Application. Vol. 17, no. 2, Desember 2017, hlm. 60-76, https://jurnal.ugm.ac.id/v3/AJChE/article/view/8982.